CALGARY, Alberta — A vacationing family of four from California was Saturday confirmed dead in a fiery three-vehicle crash in Canada.

The couple, aged in their forties and from Palo Alto, Calif., were traveling with their 12-year-old son and 10-year-old daughter, Royal Canadian Mounted Police (RCMP) confirmed.

The accident occurred at 3:05pm local time Friday on Highway 93 in Kootenay National Park, British Columbia, 80 miles (128km) west of Calgary.

All three vehicles were destroyed when a tractor trailer crossed the highway’s center line and jack-knifed into the oncoming Dodge camper van, which was towing a Suzuki Sidekick compact 4×4, the Vancouver Sun reported.

The driver of the truck, a 40-year-old man, escaped unharmed after motorists stopped to assist, however flames had already engulfed the other two vehicles.

Police were initially unsure how many people were inside the van, due to the extensive damage to the vehicle, or its owners and origins. Forensic investigators examined the vehicle after it was moved to another location on Saturday.

The RCMP said it was working with authorities in the United States to notify the next of kin of the Californian family, who had arrived in British Columbia on July 21.

The driver of the truck was interviewed by authorities.

“We’re looking at the mechanical conditions of the vehicle to determine whether mechanical failure was a factor,” RCMP spokesman Cpl. Dan Moskaluk said.

“Then [we will] look at the actions of the truck driver as to what caused his vehicle to come over across the center line and jack-knife into traffic.”